Question

HELP.

The number of reports of a certain virus has increased exponentially since 1960. The current number of cases can be approximated using the function r(t) = 207 e ^ 0.005t, where t is the number of years since 1960. Estimate the number of cases in the year 2010.

Answer 1

The number of cases in the year 2010 is 266.

Explanation:

An exponential function is one that the independent variable x appears in the exponent and has a constant a as its base. Its expression is:

f(x)=aˣ

being a positive real, a> 0, and different from 1, a ≠ 1.

In this case:

`r(t) = 207*e^(0.005*t)`

where t is the number of years since 1960 and e is an irrational number of which it is not possible to know its exact value because it has infinite decimal places. The first figures are 2,7182818284590452353602874713527 and is often called the Euler's number. e is the base of natural logarithms.

In this case, you want to know the number of cases r (t) in 2010. So, to know t you must know how many years have passed since 1960. For that, you can simply do the following subtraction: 2010-1960 and you get as a result : 50.

Replacing in the exponential expression r (t):

`r(t) = 207*e^(0.005*50)`

Solving:

r(t)=265.79 ≅ 266

The number of cases in the year 2010 is 266.